1. Field of the Invention
This invention relates to an electromechanical cryocooler that reduces or cancels out vibrations generated by the cooler.
2. Description of Related Art
Cryogenic refrigerators, or cryocoolers, are used to cool highly sensitive instruments, such as radiation detectors, spectrometers, and chromatographs. The detectors typically must be kept at extremely low, constant temperatures to reduce thermal noise. The use of cryocoolers has continued to increase with the demand for portable, rugged, and reliable instruments for field measurements.
Cryocoolers use a piston that is cyclically driven to compress and expand a working fluid. Although thermodynamically efficient, these cryocoolers have the adverse effect of vibrating. The measurements of the detector may be corrupted by motions of the detector, and therefore these vibrations must be reduced for the detector to work accurately. Conventional designs for mechanically cooled instruments have no mechanisms for substantially eliminating vibrations that can interfere with the optimum operation of the instruments. Typical methods for reducing adverse effects due to mechanical forces include vibration damping by adding to the cooler mass or by adding vibration-decoupling supports to the cooled object.
These conventional techniques are undesirable, especially in applications where reduced size, low weight, minimum power use, and robust field performance are critical. Thus, there is a need for a cryocooler that significantly reduces adverse vibration effects in mechanically-cooled systems.